What would be the standard rear axle ratio for a '63 Wildcat. 401 dynaflo. Are there any identifiying tags or numbers I should be able to find.
The standard ratio for the Wildcat (models 4639, 4647, and 4667) was 3.42 in 1963. The ratio should be stamped on the bottom of the axle housing under the center section. It will probably be hard to read so you will need to spray some penetrating oil on it and clean it off. The number 4 with the number 2 below it means 3.42. There should also be another number in the range of 1-365 which represents the production day. If it is a posi, there might be a stainless steel plate around the filler plug that says "USE LIMITED SLIP DIFF. LUBE ONLY". For a posi, there will also be a the letter X in a 0.5 inch diameter circle stamped on the bottom of the carrier housing flange, but this is usually very hard to see.
hi, I have same problem/question but about axle ratio in buick skylark '72, 350 2bbl with auto trans. Can You help?
Look on the axle tubes between the spring perch and the cast center. Buick can be on the back of the tube some on the bottom of the tube driver side tube chevy rears will be on the passenger side front of tube. Easiest way is always to open the rear cover and read the edge of the ring gear spin it till you find the stamped in numbers - that is the only true way to tell what you have. Jim
Hey Thanks for the replys. The next time I get it up in the air I'll check for numbers. I don't think it has a removeable rear cover.
Oops did not see the year..My fault. Could try the spin test BUT you need to remove the wheels drums etc. Then mark the axle to the backing plate with caulk for a reference point and do the same onthe yoke flange and casting center mark it for reference point. NOW spin the YOKE (only spinning the yoke will make this work correctly as you do not want the spider gears to turn) See how many times the yoke spin compared to one complete revolution for the axle around and back to its reference point. BE sure not to loose track of the number of spins the yoke makes. TAke care, Jim Reason for the wheel and drum OFF keeps the resistance off the spider from spinning and messing up the test.
The standard rear for that car should be 2.56, but lots of things could have happened in 39 years. Is it a 10 bolt, or 12 bolt rear?
its standart 10 bolt and looks oryginal - all car was complete and stock. now I have removed axle and opened cover but I couldn't find any numbers... but unfortunatelly I suppose it's 2.56... How can I change ratio? I bought manual gearbox and this ratio will be too small I think so... what ratio I'll need to buy and how it change?
The edge of the ring gear should have the part number and the gear tooth count of both the ring and pinion stamped into the outer edge. Example picture.
www.fotosik.pl/pokaz_obrazek/08b94097ed77a4eb.html http://www.fotosik.pl/pokaz_obrazek/af05c829ca111447.html i found this numbers... what it means???
I found a 3 stamped above 42 on the bottom of the center of the housing so I assume it is a 3:42 and that is consistant with what should have been standard it seems. Thanks for all the responses
Look for two double digit numbers like in Mozaz's photo. In that photo, 42, and 13. 42 divided by 13, would be 3.23.
16 41 is 2.56 2nd picture 1234476 Is the actual part number for the 2.56 gear in that rear size 1st picture so there you have it 41 / 16 is your 2.56 rear. Take care, Jim
thanx 4 reply! so from what car I can buy new ratio and change it, because with manual gearbox this ratio won't be so nice... can I put inside something from more popular chevy models, where find and buy it?
If you have the popular 8.5 10 bolt, there are plenty of parts available. Contact Monzaz and he will set you up with whatever you need.
